Hydraulic lifting jack



J. ERHARDT HYDRAULIC LIFTING JACK Apr. 24, 1923. 1,453,043

Filed Aug. 5. 1921 4 s n j i 5f Patented Apr. v24, 1923.`

uruTED` STATES PATENT oFFlcE.

JOSEPH ERHRDT, 0F CHICAGO, ILLINOIS. i

HYDRAULIC LIFTING JACK.

To all 'whom z'tmafy/ concern.'

Be it known that I, JOSEPH EBHARDT, a

v citizen pf the United States, residing at Chicago, in the county of Cook and State of `Illinois, have invented a `certain new and The invention has among its various ob jects the p`rov1sion of a device of tlus charac- V lter which is relatively smallv in size and capable of use as an automobile accessory, and

- which is simple in construction, efficient in operation and relatively light in weight so that it may be readily transported orhandled when its use is found necessary.

The invention hasv an additional object, the provision of an arrangement in which the lifting element may be actuated to lift an object and maintain itin an elevated position.

It is a further object of the invention to provide a structure lsuch as above described with a means for releasing the pressure .from the lifting element so'that it may be lowered, this means being capable of adjustment so as Vto regulate the speed at which the lifting element receeds from its elevated position.

Itis also an object to provide a construction in which the pressure applying element may be manually actuated 'and the pressure created maintained until released without being transmitted tothe pressurey creating mechanism. This assists in permitting the manually operated pressure device to be readilyr actuated and eliminates back pressure, which adds to the case of the operation` of the pressure creating device.

The particular arrangement herein shown ffor accomplishing the desired result includes the 'use of a fluid reservoir,` a fluid pressure cylinder, a lifting element whichcis arrangedk for movement in the pressure cylinder and a fluid pressure creating device which acts upon the lifting device. This pressure creating device is arranged below'` the `pressure cylinder and communicates therewith. The

passage forming the communication betweenthe pressure cylinder and-thepressure creating device is controlled by a valve whichl permits the fluid to pass from the pressure Creating device to the pressure cylinder, but

Application led August 5, 1921. Serial No. 489,933.

prevents the flow of said fluid from the presi sure cylinder back into or toward the pressurecreating device. Y.

The pressure creating device and the fluid reservoir communicate with each other,y the fluid being permitted to flow from the reserv oir towards the pressure creating` device but is prevented from flowing in the reverse direction. l j

By this arrangement just described the fluid may flow into the pressure creating device and be forced thereby into the pressure chamber against thelifting element causing it to raise, vit being held in this raised position by virtue of the fact that the fluid is `prevented from flowing back into the pres? n sure creating apparatus or from the pressure cylinder.

A bypass is provided which leads from the pressure cylinder back to the fluid reseri voir. Thisby pass is controlled by a valvel which is closed during the lifting operation of the lifting element. This valve prevents the flow or escape of the pressure from the fluid pressure chamber to the fluid reservoir, but is operable to allow the pressure to gradually escape from the pressure cylinder backy into the fluid chamber or reservoir.' The valve which controls the flow of the fluid is capable of adjustment to vary the speed at which the lifting element is flowered andv is also operable to permit the lifting device to be partially lowered and held in this last named position, -froinwhich position it may be fully lowered. v

The lifting device is also capable of being manually raised to any desired elevated position `and its elevation increased Afrom this manually set position by the actuation of the pressure lcreating device. f

The invention will be explained and more readily understood when read in conjunction u'ithth'e accompanying drawings which show one embodiment which the invention is susceptible, it being obvious that other a-rrangements'may be Yrsorted to without departing from` the spirit of the appended,v

claims forminga part hereof- VIn the drawingl Fig. 1 is a central' longitudinalsection of a jack constructed according to 'one embodiment of the invention.Y

Fig. 2 is a section taken on line 2-2 of Fig. 1.

" In the particular embodiment of the in'- `vention illustrated yin the drawings, the use of a ba 10 is contemplated.. The upper vlos' most end of this base is'v provided with an annular projected portion 11, the outermost face of which is provided with screw threads which cooperate with screw threads provided on the tubular element 12 which roduces one wall of a-fluid chamber 12. he uppermost end of this member 12 is closed by an annular plug 13, it being provided with the threads 14 which cooperate with the threads on `the tubular member to secure these two portions together.

The inner annular face of the projection 11 is also provided with threads as shown at 15 and these threads cooperate with the threaded end of the tubular member 16. This member 16 together with the tubular member 12 produces the fluid chamber 12a. This tubular member provides a pressure cylinder. This last mentioned tubular member 16 extends upwardly into engagement with the member 13, the end being held within the recess 17 of this member 13. A suitable packing 18 is interposed between the uppermost end of this tubular member 16 and the member 13. This prevents leakage of the fluid from the reservoir or fluid chamber provided by the tubular members 12 and 16.

A plunger or lifting element 19 is arranged for reciprocation within the tubular member 16. This lifting element` 19 projects through the plug 13 and has its uppermost end provided with a head 2O which is placed against the article to be lifted. This lifting element 19 is packed against leakage by the packing 18, the latter being arranged within the plug 13 and is held by the collar 22. The lowermost end of this mem-ber 19 is provided with the reduced portion 23 upon which is arranged the ring 24 and the cu shaped portion 25,botl1 of which are helld with respect to the lifting element 19 by means of the nuts 26. These parts 24 and 25 provide a tight connection with the tubular member 16 but permit the lifting element 19 to be raised when the pressure is applied thereto.. y

This structure provided by the elements 24 and 25 simulates aI piston head as will be evident from the following.

A pressure creating device generally designated 26 is utilized. This pressure creating device includes the plunger 27 and the cylindrical bore 28, this bore being provided in the base 10. A .valvecontrolled passage 29 communicates with the pressure cylinder` produced by the tubular member` 16. This passage 29 is arranged so that the fluid which is pumped or put underl pressure by the plunger 27 is permitted topass from the cylindrical bore 28 through the passage into the pressure cylinder below the lifting element, thus when the fluid, which in the present instance is oil, is pumped by the plunger 27 through the ypassage 29 this pres- `bore of the pressure creating dev1ce. vvalve controlled bypass 1s utilized to permit sure will be exerted upon the lowermost end of the lifting element 19 which will cause it to lbe raised.

A pressure actuated valve 30 is arranged in the passage 29 betweenthe cylindrical bore 28 and the pressure cylinder formed by the tubular member 16. The plunger' 211s provided with a reduced portion 31 and the leather or other cup shaped portion 32 which is placed over the reduced portion 31 and clamped to the plunger 27 by means of the nuts 33.

This plunger 27 is packed as shown at 34 and this packing is held by means of the collar The lowermost end of the plunger 27 is provided with an exagainst leakage tension 36 having a head 37. This last men-l tioned portion is designed to be engaged by the forked or bifurcated end 38 of a lever 39 which is pivoted to the base 10 lat 40. Thus by actuating the handle or lever 39 the plunger 27 will be caused to reciprocate within the cylindrical bore 28 causingthe fluid therein to lbe forced therefrom into the pressure chamber produced by the tubular member 16. This will cause the plunger 19 to be elevated.

The fluid within the pressure chamber is prevented from passing back into the cylindrical bore of the pressure creating device by means of the check valve 30, thus this lifting element 19 will be raised and maintained in its elevated position.

A fluid passage 41 is produced which extends through the collar or extension 11 and communicates with the cylindrical bore 28 through the passage 42. The passage 'of the fluid from the reservoirV 12a to this cylindrical bore is controlled by a ball check nalve 43' which is operable to permit the fluid to be introduced into the cylindrical bore upon the suction stroke of the plunger 2 but prevents the fluid from passing back into the fluid reservoir upon the compression stroke ofthe plunger. This ball check is caged within the end of a removable plug 44 which is provided with a head 45 and the screw threaded portion 46 so that it may be readily removed and inserted for operation withv respect to the fluid passages above enumerated. This plug 44 is provided with the annular grooved portion 47 and the radial passages 48 which communicate with thepassage 49, thelatter terminating in a seat for the ball. check valve.

The last mentioned arrangement permits the from the -fluid chamber into the cylindricl the regulation of thelowering of the lifting element 19. This bypass connects the pressure cylinder and the reservoir together and is controlled by an adjustable ball check 'valve which may be regulated to allow the plug to be inserted and the fluid to pass4 ervoir 12a. "These passages 49 and 50 are provided in the baseand the ball check 10 valve is interposed between them so thepassage of the fluid from one to the other may be regulated. This ball check regulating mechanism includes the member 52 which is threaded into al suitable threaded 15 opening eThis member 52 carries the set screw 54 which is adjustably arranged within the member 52-and has the end 55 thereof provided to engage and release the ball vof the ball check valve 51. This set screw 54 is secured to the member 52 by means of the threaded portion 56.

By referring to the drawings it will be evident that by manipulating this set screw 54tl1at this ball of the check valve 51 may j be securely held against its seat to preventl the passage of the fluid from the pressure cylinder into the reservoir and may be also adjusted so that various openings are pro- 4duced between the ball of the ball check valveand its seat, which therefore regu? lates the amount of 'fluid which may pass from the pressure cylinder into the reservoir 12a.

From the foregoing description it is evident that the lifting .element 19 maybe manually lifted or moved with respect to the remaining structure and elevated by the operation of. the plunger 27 from this manually set position or this plunger may be 40 caused to travel from its lowermost posi-tion as shown in the drawings to any one of its intermediate )ositions b v the actuation of the plunger 2 through the medium of the lever 39. `v j The operation of the device is substantially as followsz' B v operating the lever 39 the plunger 27 will be actuated or reciprocated in the cylindrical bore 28. Upon its downward or suc- :tion stroke the ball check 43permits the vfluid to pass from the reservoir 12a through `thc passages 41, 42, 47, 48 and 49 into the cvlindrical. bore' 28. `At this time the ball check 30 rests against its seat which prevents vany `fluid, in the pressure chamber'from entering this cylindrical bore 28. Upon the upward or compressed stroke of the plunger 27y the fluid in the cylindrical bore 28 Will be forced through the passage 29 into the presy sure chamber below the lifting element 19.

.Y Upon this stroke of theplunger the ball i. check valve 30 is unseate'd and the ball cheek 05 Voir 12a. This Operation is continued until opened to the lifting element 19 is raised to the desired position. During this operation the ball of the ball check valve 51 rests against its seat which prevents the fluid in the pressure chamber from passing therefrom through 7.0 the passage 49. Then it is desired to permit the raising element 19 to lower this ball check 51 will be released fromvits contact with the valve seat by the manipulation of the set screw 54. This allows the fluid in the pressure cylinder to pass through the passages 49 and 50 back into the reservoir 12. The pin 40 of the valve handle 39 may be separated from the base 10 which permits the separation of the 80 handle or lever and the base so that the a1'- rangement will not consume any great amount of space when not in use.

,Having thus-described the invention Wha-t I claim and desire to cover by Letters Patent is:

' I claim:

1. In a portable lifting device the combination of a member providing a'base for the lifting device, said base having a. fluid chamber and a pressure chamber secured thereto, a lifting element arranged in the pressure chamber, said base being provided with a chamber which communicates directly with the pressure chamber, a pump ar- 95 ranged inthe chamber, a Wall of the pump chamber providing a wall for the pressure chamber, a valve. arranged in said Wall, a h

\ passage leading from the fluid'chamber to' said pump chamber and a passage'leading 100 from the pressure chamber to the fluid chamber. y -2. In a portable lifting device the combination of a member providing a base for the liftingl device, said base having 'a fluid chamber and a pressure chamber secured thereto, a lifting element arranged in the pressure chamber, said base beingk provided with a chamber which communicates directly with the pressure chamber, a pump arranged in thechamber, a Wall of the pump chamber providing a Wall` for the pressure chamber, a valve ,arranged in said Wall, a' a passage leading from the fluid chamber to said pump chamber, a passage leading from the pressure chamber to the fluid chamber, a valve' arranged in both of said last named passages, said last mentioned valve being closed during the lifting operation and permit the lifting element to be 120 lowered.

3. In a portable 'lifting device the'v combination of a Amember providing a base fon the lifting device, said base having a Huid chamber and a pressure chamberj secured thereto, said lifting element arranged in the pressure chamber, said base being provided with -a chamber which communicates directly with the. pressure chamber, a pumparranged in the chamber, a wall of the pump 13o chamber providing a wall for the pressure chamber, a valve arranged in said wall aI thereto, said lifting element arranged in the pressure chamber, said base being provided with a chamber which communicates directly with the pressure chamber, a pump arranged in the chamber, a wall of the pump chamber providing a wall for the pressure chamber, a valve arranged in said wall, a

passage leading from the fluid chamber to said pump chamber, a passage leading from the pressure chamber to the fluid chamber, said pump chamber and pressure chamber being arranged in substantial axial alignment with each other.

5. In a ortable lifting device, the com` bination of) a member providing a base for the lifting device, said base having a fluidl chamber and a pressure chamber secured thereto, a lifting element arranged in the pressure chamber, said base being provided with a chamber which communicates directly with the pressure chamber, a pump arranged in the chamber, a wall of the pump chamber providing a wall for the pressure chamber, a valve arranged in said wall, a passage leadin from the fluid chamber to the pump cham er, a passage leading from the pressure chamber to the fluid lchamber, said pump chamber, pressure chamber, and fluid chamber being arranged in substantial axial alignment with each other. p

6. In a hydraulic jack, the .combination of a base, a member forming a chamber secured to said base, a .lifting element arranged in said chamber, a pump chamber provided in said base, said pump chamber being in communication with said first mentioned chamber, a nlungerrprovided in said pump chamber, the lowermost end of the pump chamber being arranged in spaced relation to the lowermost part of the base to provide a spacein which the plunger may be removably secured thereto.

7. In a hydraulic jack, the combination of a base, a pressure. chamber and a fluid chamber secured `to base, a lifting element arranged in the pressure chamber, a pump chamber provided in said base, a valve controlling the flow of fluid from the fluid chamber to said pump chamber, and a valve controlling the flow of fluid from the pressure chamber tothe \fluid chamber, said pump chamber being arranged in spaced relation to the lowermost part of the base. to provide a space in which the plunger may operate and said Yplunger being provided with means whereby an element for actuating said plunger may be removably secured thereto.

8.. In a hydraulic jack, the combination of a base, a member formin a chamber secured to said base, a lifting e ement arranged in said chamber, a pump chamber provided in said base, said pump chamber being in substantial axial alignment with the first mentioned chamber and being in communication with said first mentioned chamber, a plunger provided in said pump chamber,`the lowermost end of the pump chamber being ar' ranged in spaced relation to the lowermost part of the base to provide a space in which the plunger may operate, said plunger h ing means whereby an element for actua lng said plunger may be removably sec red thereto. i

9. In a hydraulic jack, the combination of a pressure chamber, a lifting element arranged insaid chamber, a pumpchamben provided in said base, a plunger arranged in said pump chamber, and said plunger be- Y ing arranged for vertical reciprocation below said pump chamber.

10. In a hydraulic jack, the combination of a pressure chamber, aliting element arranged in said chamber, 'said base being bored to provide a pump chamber, a pump arranged in said pump chamber, means for actuatin` said pump and said base being provide with'a space foJr` the reception of said means for actuating said pump.

In witness whereof, I hereunto subscribe. my name this Sth'day of July, A. D. 1921.

`JosErH ERHARbT. 

